The event-free survival rates of children diagnosed with acute lymphoblastic leukemia (ALL) demonstrate the advances that have been made in pediatric oncology and, more specifically, the improved understanding of the disease's heterogeneous characteristics. Understanding of the heterogeneity, differences between ALL cases, has been propelled through genetic classification of the leukemia, molecular monitoring of treatment response based on the genetic classification of the leukemia, and an understanding of the individual patient's variability in response to treatment. It is the culmination of the genetic profile of the leukemia, the individual patient, and molecular monitoring that has led to the earlier identification of patients who respond less favorably to treatment and thus prompts their treatment intensification and improved outcomes. It is imperative that nurses become knowledgeable of leukemic genetic markers and molecular monitoring and their clinical significance when caring for the child and their family.